Abstract: A transmission including at least two shafts and a cylindrical member supported by a frame for rotation relative thereto about axes of rotation utilizes a pair of gears and a plurality of speed-adjusting teeth for altering the relative speed of rotation between the shafts and the cylindrical member. Each of the gears is connected to a corresponding one of the shafts for rotation therewith, and the shafts are appropriately coupled to one another so that rotation of one shaft effects a rotation of the other shafts. The speed-adjusting teeth are disposed about the cylindrical member and cooperatively mesh with the gears for transmitting rotary motion between the shafts and cylindrical member and so that at any rotational position of the cylindrical member about its axis of rotation, the speed-adjusting teeth are in meshed relationship with at least one of the gears.